LANSING, MI - A bill aimed at boosting Michigan’s horse racing industry will not be signed by Gov. Rick Snyder, who considers the plan likely to be unconstitutional without the approval of voters at statewide and local levels.

The measure – House Bill 5546 – was approved by the Michigan Legislature late last year. But because Snyder will not sign it, the measure will be “pocket vetoed” – meaning it will expire this week and won’t become law.

The measure was aimed at allowing raceways to install machines allowing customers to place bets based on historical horse races. The goal was to provide a new gambling attraction to help draw more customers in an era when horse tracks have lost ground to casinos and lotteries.

The Snyder administration says the bill likely would be deemed unconstitutional. The administration says statewide and local votes would be needed to authorize this form of gambling, spokesman Caleb Buhs said in an e-mail Thursday.

In 2004, Michigan voters approved a constitutional amendment that requires some types of gambling expansions to get approval from state and local voters. Supporters of House Bill 5546 said they do not believe the 2004 measure would have applied to their plan and that votes of the people would not have been required. But some casino interests disagreed, and it appeared legal challenges would have been likely had Snyder signed the measure into law.

Michigan’s horse racing industry has been in decline for decades, overshadowed by casinos and other forms of gambling that have become more prominent across the state.

Horse tracks have wanted to add attractions such as slot machines or other casino games for years, but they’ve been denied – mostly because of efforts backed by casino owners who don’t want the competition. In 2004 – as horse racing tracks pushed for permission to add slot machines -- casinos supported the constitutional amendment to require most types of gambling expansion to be approved by voters. The constitutional amendment, which voters approved, does not apply to Detroit's three casinos or Indian tribal gaming. But it does apply to horse tracks.

The legislation that Snyder won’t sign had sought to allow machines that have a catalog of thousands of already-run horse races from around the nation. Bettors are not provided with the location or date of the race, or the names of horses or jockeys. But they do have access to some of the same data that would be provided in programs for live races.

Supporters of the legislation had said that should not be considered an expansion of gaming, but rather a continuation or adaptation of gambling that’s already allowed.